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comment Relation of the cross product of the functions to the cross product of their Fourier spectra
What do you mean by "cross product" ? on my browser, at least, the math is not rendering correcctly, I cannot see the formulas. Do you simply mean the pointwise product of their values?
11h
comment Quantum field theory's interpretation of double slit experiment
I disabled video on my web browser when that security hole came out three years ago....No, I am referring to a book. But it was his considered opinion, so he probably said it out loud many times in many places. I think he was wrong, indeed, wrong-headed.
13h
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13h
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16h
comment What is the solution for the apparent contradiction of Second law due to energy fluctuation?
@Wolphramjonny In English, it is better not to say "can not" if you mean "might not". Foreigners often mix up "can" with "might" If you say "it can not happen" that's actually not English at all. One says either "It cannot happen" (= "it can't happne" = it's impossible) or 'it might not happen" (= it is possible that it does not happen"). Sorry, but the helper verbs, negations, and subjunctive in English are like wicked difficult....
17h
comment Quantum field theory's interpretation of double slit experiment
I agree with you. But Feynman disagreed with us. It is hard to draft a technical paper which will prove who of us is right. Well, okay, I know I am right...always right...about everything....jajajaja And you too, of course. But like Weisskopf said, "Well, you don't get a Nobel prize for being right."
18h
comment Quantum field theory's interpretation of double slit experiment
Manuscripts that don't have, as ultimate payload, something "technical", are hard to publish becuase it is hard to decide if they are worthwhile, make some kind of advance, etc. Even if correct! Feynman wanted to eliminate waves, he said this explicity, in the context of QM. I'll find the reference somewhere...either the LEctures on Physics or the Feynman--Hibbs book or something. He explicitly said the whole Bohr balancing act between wave--particle duality was unnecessary. Particles exist, waves are merely mathematical devices for computing transition amplitudes, according to him.
18h
comment How can a product of Bra and Ket be a scalar if they are matrices?
Linear means it preserves "linearity": f(ax+b)=af(x) + f(b). If you change coordinates by moving the origin, you will produce a function g that violates this. Consider the one-dimensional vector space. Any linear function must take the value zero at the origin. If you change the origin, that same function will no longer have that property, it will take the value zero at the old origin, not at the new origin, so it won' tlook linear anymore. In the new coordinates, it won't be linear. It was linear in the old coordinates.
18h
comment How can a product of Bra and Ket be a scalar if they are matrices?
The scalar will not change either. Most matrices will change, but not one-by-one matrices (neither will diagonal matrices all of whose diagonal entries are the same). Oh, and, BTW, since we are talking about linear transformations, only linear changes of coordinates are considered, so changing the origin is never done. This is not just any arbitrary space, it is a vector space, so it has a linear structure. ONe would never introduce different coordinates that would hide this linear structure. (General Relativity, of course, does precisely this....because its spaces are not vector spaces.)
18h
revised How can a product of Bra and Ket be a scalar if they are matrices?
added 743 characters in body
18h
answered How can a product of Bra and Ket be a scalar if they are matrices?
18h
comment Probabilistic vs Statistical interpretation of Double Slit experiment
This is not very accurate.. The logic of vector spaces is certainly deducible from set theory. In fact, all of probability can be formulated in terms of the theory of deterministic sets and deterministic real numbers. For example, no new kinds of "random" numbers need to be invented. The same holds for quantum logic: it is completely expressible in terms of ordinary Boolean logic.
19h
comment Quantum field theory's interpretation of double slit experiment
A lot of physicists agree, in private, with that article. More or less. But cannot publishe because---it isn't really anything definite and physical out of that mantra that differs from the opposite point of view. The complte opposite point of view was Feynmans's: he wanted to eliminate wave--particle duality by eliminating the waves. He, in effect, said, there are no waves (they are only a mathematical device), there are only particles. Perhaps I will write this up as an answer
19h
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2d
comment What is the definition of physically meaningful?
This answer is what is called "logical positivism", a kind of philosophy of science, which was widley accepted by many physicists for a long time in the twentieth century, but which has been criticised by Feynman, Wienberg, and Gell-Mann. Anyway, it is a particular philosophy, and is not part of science itself. Science itself has no definition of "physically meaningful".
Jan
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Dec
9
reviewed Approve How does friction act in rolling motion?
Dec
9
answered What does “the fabric of space and time” actually mean?
Dec
9
comment Proving that the Center of Mass of a solid sphere is at the origin
To get the centre of mass, you have to multiply by the coordinate, x. /because of leverage). But what it multiplies is mass, which is always positive. So the integrand can not be an even function. As the other poster said, don't use spherical coordinates, use Cartesian coordinates